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Teac LPU190 with digital display not turning on

Discussion in 'Troubleshooting and Repair' started by errol-smith, Oct 14, 2014.

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  1. errol-smith

    errol-smith

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    Oct 14, 2014
    I have acquired a Teac LPU190 record player/radio/USB/amplifier thingy with an annoying digital display.

    It won't start. If you leave it off for about an hour, when you apply power the screen lights and then goes dark again. The standby LED is lighted but pressing "standby" does nothing. If you then try again, it doesn't even light the screen.

    I thought it was that it needed the clock set, but pressing "mode" for a while also does nothing,

    I got it work a couple of times by pressing a combination of buttons but I can't remember what they were. As long as it was plugged in, or re-plugged in within a short period of time it would work.

    ----
    It seems to use an IC from a clock radio/TeasMaid thing but they haven't connected all the pins. It has a clock but no alarm or sleep mode. You have to press and hold "mode" to view the clock like an old Sinclair digital watch.

    It doesn't have flash memory, just a capacitor or CMOS latch or something. Once its "forgotten" the time it goes back to not working.

    It seems like the IC is going into "sleep" mode and turning off when you switch it on. I had another thing that kept doing that but I can't remember how I got it to work.
     
  2. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,268
    Nov 28, 2011
    TEAC-LPU190-turntable.jpg
    Oy vey! That looks tacky!

    Can you start by showing us some photos of the general layout and the circuit boards. Also, what are the markings on the clock IC?
     
  3. errol-smith

    errol-smith

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    Oct 14, 2014
    I managed to "catch it doing good" last night, but again I forgot what was the sequence.
    It had the clock showing, but not lit up, just with black writing on a black background, then I pressed "Standby".

    It has 5 circuit boards, which appear to come from different sources. What I think is the clock-latch IC is surface mounted so not replaceable :
     
  4. errol-smith

    errol-smith

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    Oct 14, 2014
    Here are some shots :
     

    Attached Files:

  5. errol-smith

    errol-smith

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    Oct 14, 2014
    and
     

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  6. errol-smith

    errol-smith

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    Oct 14, 2014
    and
     

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  7. errol-smith

    errol-smith

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    Oct 14, 2014
    and
     

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  8. errol-smith

    errol-smith

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    Oct 14, 2014
    and
     

    Attached Files:

  9. errol-smith

    errol-smith

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    Oct 14, 2014
    Sorry for the multiple posts but the internet is incredibly slow at the moment and it kept losing the files.

    What I think is the clock/latch IC which is in the "USB-counter" jpeg, has this written on it :

    ALi MS675 A1
    1312 G51 XHGJX10008GE

    I think the "G" may be a Euro symbol though.
     
  10. KrisBlueNZ

    KrisBlueNZ Sadly passed away in 2015

    8,393
    1,268
    Nov 28, 2011
    OK, so the clock is informational only? In that case, it shouldn't be affecting anything else. Are you sure it doesn't have alarm or sleep functions?

    Is the Standby LED always illuminated when it's plugged in? But the pushbutton doesn't do anything? Can you trace the tracks from the Standby pushbutton and find what they connect to? Does one of them go through one of the the four wires at the bottom of the front panel board? If so, where does that wire go?

    Can you trace the flow of power from where it enters the unit? Is there a transformer, or does it use an external adapter? Follow the power to see how it gets to the main board. That little board in post #8 has an electrolytic on it - that might be involved. Where do the two blue wires go? Where do the red and black wires go?
     
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